Naperville residents Dakota Lohman, 8, and Rahadi Lohman, 11, fill buckets with sand, while Isabel Lohman, 13, runs by. The family was among the first visitors to Centennial Beach when it re-opened Saturday after undergoing renovations during the offseason.Daniel White | Staff Photographer

This swimming season starts a new era at Centennial Beach in downtown Naperville.

Visitors to the beach's grand reopening Saturday experienced the very beginning of the new era, as the beach welcomed the public for the first time since closing last Labor Day to undergo major renovations.

The bath house, a fixture at the 500 W. Jackson Ave. swimming hole since it opened in 1931, is the star of the renovations, Naperville parks officials said Saturday.

"We started with seeking community input about how to renovate this," said Naperville Park Board President Mike Reilly, pointing at the bath house.

The consensus: add family changing rooms, make the space more accessible to people with disabilities, decorate with posters and photos detailing the beach's history -- and do it all without losing the building's historical character, Reilly said. The renovated beach also has a new concessions building, a lift to bring people who use wheelchairs down to the swimming deck and new restrooms on the deck level.

Renovations were budgeted at $5.5 million, said Naperville Park District Executive Director Ray McGury. But even facing weather delays like the early February blizzard and about three inches of rain in the project's final few days, McGury said he expects the project to come in "significantly" under budget.

Timing of the renovation is ironic, Naperville City Councilman Paul Hinterlong said. Planning began in 2008 and construction took place between September and May.

"This park was built back when this nation had its worst economic downturn in history," and it brought peace and relaxation to many at that time, he said.

And now the beach was renovated during what some are calling the "Great Recession," and what Hinterlong called the second-worst economic downtown in American history.